Abstract: A handheld modular digital photography system is provided. A lens assembly includes a plurality of lens elements aligned on an optical axis to form an optical image on a plane of a digital image sensor. Both the lens elements and image sensor are fixedly mounted within a lens barrel. The image sensor is electrically-interfaced to a controller with a wireless transceiver. A modular chassis includes a structural frame, lens mount, and shutter control. The structural frame includes a cradle shaped to securely hold a handheld mobile device and an electrical coupler configured to electronically interface with the mobile device. The lens mount is on an outer surface of the modular chassis. The shutter control is provided to electrically signal the mobile device. The mobile device wirelessly sends the signal to the controller, which triggers image capture by the image sensor and wireless relay of the captured image to the mobile device.